SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '623f013057c9b3b6b84e1bd71585684903296997fa46dfa70c5a6ff2f39476a2' 
  AND token = 'd34mgK9gAm0kGA+BB+08QlNjf87LpjcyhcynbYwmcJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}